Using the back of a spoon, form a disc 10 cm (4 inches) across with 10 ml (2 teaspoons) melted chocolate. Sprinkle with pistachios. Repeat for a total of 8 discs. Refrigerate until the chocolate has completely hardened, about 15 minutes. Carefully loosen the discs from
Place the orange segments in a bowl. Set aside.
In a saucepan, bring the orange liqueur, water and sugar to a boil. Pour the hot syrup over the orange segments. Stir gently to coat the segments. Refrigerate for
On 4 dessert plates, stack the orange salad and chocolate discs (2 discs per plate) in alternating layers, starting with the oranges and ending with a disc.